Facts that you should know:
A proprietary author ID fully integrated with Web of Science: ResearcherID is a unique identifier system that integrates with Web of the Science (WoS) to address author name ambiguity issues. Authors register for a ResearcherID on voluntary basis. With a ResearcherID, authors can manage their publication lists in their Researcher profile, track the citation counts and h-index of their publications indexed in WoS (read more here). ResearcherID is now ORCID compliant.
Things that you should do:
Update your Researcher profile from time to time: Web of Science will not map articles to your Researcher profile automatically. When users search for your publications in WoS with your ResearcherID, they are actually retrieving the publication list maintained by you in your Researcher profile. Therefore, to enable users to locate all your WoS publications by means of your ResearcherID, you need to keep your profile up to date. This will also ensure that the citation metrics you generate from your Researcher profile cover all your works without omission.
ResearcherID is not a must for integration with Web of Science: Web of Science has now enhanced its functionality by including ORCID information in its database with monthly update. For authors without a ResearcherID, their works can now be searched in Web of Science by means of their ORCID iD as long as they have maintained their ORCID publication list.